This patent relates to shielded structures for gripping and removing objects, while protecting the user.
The closest patent known to the inventor combining a closing structure with an internal gripping means is U.S. Pat. No. 3,124,984 to Anderson. Anderson discloses a wrench, in the sense of an object that provides a torquing motion to a cylindrical object, in which an enclosing cylindrical container has an internal friction band which is tightened by means of a roller cam against the object to be removed. However, Anderson's cam structure compressingly engages a free end of a helix against the cylindrical object and can only be used in torque. Anderson specifically mentions that separate wrenches must be provided for the two normal directions of torque (clockwise or counterclockwise). It appears that Anderson's structure would apply insufficient gripping power for a straight backwards pull.
U.S. Pat. No. 4,648,582 to Grundahl discloses various forms of strap wrenches for gripping or clamping a cylindrical object. This patent discloses a screw-tightened clamping unit in which a screw compressibly engages a continuous wirerope which is led to form the clamping member of a u-clamp. The device is described as having utility for holding a shaft for lifting.
U.S. Pat. No. 4,037,495 to Beckstead discloses a form of strap wrench using Velcro as the strap fastening means.
U.S. Pat. No. 2,959,994 discloses a cylindrical housing for fitting over and gripping a screw-on spin-up filter canister; the housing contains a precoiled spring, which has a normal position tighter than the object to be grasped. Sliding the housing over the canister expands the spring, creating a gripping force.
U.S. Pat. No. 4,307,633, another form of spin-on oil filter cylinder wrench, discloses two bands, an inner and an outer, connected through a double link arrangement which cause the bands to tighten when torque is applied to the wrench.
U.S. Pat. No. 3,853,026 to Rhodes discloses an oil filter removing tool which uses spring-loaded gripper fingers which engage into the indentations found in the side of the can.